Move rule from *.rules file to UI

May I suggest using jruby

Your rule above would translate to:

require 'openhab'

rule "Bathroom night lights ON/OFF" do
  changed Bathroom_Presence_Switch, to: ON
  run { Bathroom_FloorLight_switch.on for: 2.minutes }
end

Note you’d need to configure the jruby automation addon to install the openhab helper library, as per the installation steps: Installation | OpenHAB JRuby Script Library